Jean Piaget (1896-1980) was the first psychologist to create a logical study on cognitive development. Piaget suggested that all children were born with the same mental structure, which is genetic and cannot be influenced only evolved. He considered each child as a "mini scientist" taking an active role in their environment and having to discover problem solving skills for themselves. Piaget was interested in the mistakes children make when answering questions that require them to think logically, and because of this he believed that there was a clear difference between the thinking styles of adults and adults. Due to this, most of his research involved observing children including his own. Piaget highlighted the importance of schemas, which …show more content…
However its discontinuous theme of stages can be criticised and other psychologists have found that there was an over-estimation of the ages in the formal operational stage. Keating (1979) found that 40-60% of college students fail at the formal operational tasks, and Dasen (1994) states that only one third of adults ever reach the formal operational stage. The theory of development is further criticised for being misleading and too complex, suggesting that Piaget also under-estimated the age in which a child is able to decentre. Hughes (1975) devised a realistic and relatable study to test ego-centrism in the pre-operational stage, and when the test was based on a common game of "hide and seek" the age in which a child gains this ability drops from 7 years (Piaget's results) to 3 and a half years. Piaget focused on the universality of cognitive development and was more fixated with the biological aspect of development; he failed to recognise how a child's culture and social upbringing could affect cognitive development (Vygotsky 1978.) Piaget used clinical interviews and observations to collect his results, this could therefore be open to researcher bias, as he collected the data alone and it was based on his own subjective interpretations. His theory would therefore be more reliable if it had inter-observer reliability and he worked alongside another researcher checking if their results where